Uwe Platzbecker, MD, University Clinic Leipzig, Leipzig, Germany, discusses an investigation into the correlation between the on-target activity of imetelstat with clinical benefits in myelodysplastic syndromes (MDS), as seen in the Phase II IMerge trial (NCT02598661). The trial assessed the safety and efficacy of imetelstat for patients with lower-risk MDS who are transfusion dependent and relapsed/refractory to erythropoiesis stimulating agents (ESAs). Over 40% of participants achieved transfusion independence for a period of 8 weeks or longer. In this investigation, peripheral blood samples were collected before and after imetelstat administration to analyze human telomerase reverse transcriptase (hTERT) levels. Optimal pharmacodynamic (PD) effect, defined as, ≥50% hTERT reduction by imetelstat, was seen in 54.3% of patients. These patients achieved a greater reduction in transfusions and significantly longer mediation duration of transfusion independence compared to patients who did not achieve optimal PD effect. There was also a trend towards improved median overall survival in patients with an optimal PD effect. This interview took place at the 63rd ASH Annual Meeting and Exposition congress in Atlanta, GA.